- I have seen many fake products which looked exactly the same and even have TouchWiz on JB. What's more confusing is that most of these products have a printed valid IMEI number.
- used phones might have hidden problems with their sensors, or hardware in general even if they are genuine.
01- I though I might compare the valid printed IMEI with the one I get when dialing *#06#, but I'm not sure if that number can be faked as well, can it?
02- Is there a systemic way of checking the sensors, cam, microphone, wifi etc by an app or something similar?
03- I think a benchmark tool like Antutu's can help to see the exact specs and compare them to the original ones. Can some of you take a screenshot of the exact specs as they appear in Antutut Benchmark or Android System Info.
04- How to know if a genuine S4 has been flashed before if it has an unrooted stock rom at the moment of checking?
05- Any advice on what to look for when examining a used S4?
PS: I will have physical access to the phone before buying.